This layer is a georeferenced raster image showing the sediment-thickness map of the Santa Barbara Channel region in California. This sediment-thickness map of the Santa Barbara Channel is published in Scientific Investigations Map 3225, "California State Waters Map Series--Hueneme Canyon and Vicinity, California" (see sheet 9). As part of the USGS's California Seafloor Mapping Program, a 50-m grid of sediment thickness for the seafloor within the 3-nautical-mile limit of California's State Waters from the Offshore of Refugio Beach map area to the Hueneme Canyon and vicinity map area was generated from seismic-reflection profile data, collected in 2007 (USGS cruise Z-3-07-SC) and 2008 (USGS cruise S-7-08-SC), supplemented with outcrop and geologic structure data (see sheets 8, 10, SIM 3225). The resulting grid covers an area of approximately 600 sq km. The volume of sediment accumulated since the Last Glacial Maximum is approximately 9,000 million cubic meters. This layer is part of USGS Data Series 781.In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information.